The darkness fills all your senses... and the face of an old man fades in, filling the void. "Salutations my followers, and be welcome to watch the power of the super science of the oldest human civilization of the Kree. Now watch how I created one of the most powerful human beings as a step in human evolution." The old man turns to an advanced device with a round viewing screen. "Voidorama, show for my followers my most beautiful and beloved creation: Mary Marvel Girl."

Billy Mar-Vell leaned forward again into the microphone. "Thank you, ladies and gentlemen. Since each of our WHIZ-TV Mental Marvel Quiz Kids is tied, the one who answers the final question first will be tonight's champion! Are you ready?"

The three children nodded, obviously on the edge of their seats. Billy tore open the envelope. "What are the modern names of these ancient countries: Cathay, Muscovy, Persia, and Siam?"

The attractive red-haired girl on the far right of the table raised her hand first. "They are ... China, Russia, Iran, and Thailand!"

Billy grinned. She was his favorite. "Correct, Mary Grey!" He noticed for the first time the odd locket she wore, which appeared to be broken in half ... then blushed briefly and tore his eyes away from her clavicle.

The audience applauded. "I'd like to thank our other two contestants, Freddy Rogers and Percy Pill, for also participating."

The program over, Billy escorted Mary Grey to her limousine. "Goodbye, Billy," she said, I'm very happy to have met you."

As Billy tried desperately to think of something clever to say, he felt a tap on his shoulder. It was Whitey Murphy, his assistant at the television station. Billy sighed, "Yeah, Whitey?"

The older boy grinned, "A letter came for you by messenger, said it was urgent."

Billy thanked him, tearing it open. "Dear Billy Mar-Vell," it read. "I am dying. Please come and see me. This is most urgent. Sarah Primm, 14 Elm St." In a secluded corner of the station complex, Billy wasted none of his precious time. "With only five minutes to spare until my next program," he realised, "I'd better use the speed of Captain Marvel."

Shouting the alien word "KREE!" entrusted to him by the ancient sorcerer Eon, the young boy was super-scientifically transformed into the adult hero, Captain Marvel in a blinding flash of lightning, and he soared to answer the mysterious message.

"A little twist to the right," thought the Judgement Leaguer, "and here's 14 Elm Street." He flew into an open window. "I've only used up a few seconds so far, guess I'll go in as Billy. KREE!"

Billy opened the door, having to shield his face from the smell. The interior of the studio apartment was terrible squalor; it appeared to not have been cleaned for weeks. The sickly green plaster on the walls was cracked and molding. In the center of the room was a bed, in which lay a decrepit old woman.

"Oh my gosh," Billy said, "Ma'am, please let me get you to a hospital!"

Sarah Primm raised a hand, dismissing the comment weakly. "I called for you, Billy Mar-Vell, rather than a doctor, because my hour has come ... and I have a story I must tell you ... about your parents."

"Wha ... ?" Billy blinked. "But my parents are dead. I'm an orphan."

The old woman smiled, though the effort seemed to pain her. "True, your parents J.J. and Marylin Mar-Vell are dead ... but your sister isn't."

Billy swallowed hard, "Sister?"

"In fact, a twin sister," she told him. "I was your midwife. When your parents died, I took you both to my home, before applying to an orphanage ... but I was also the midwife for a young couple, whose baby daughter suddenly died. I didn't know how I could tell the parents, and a wild scheme came to me ... I substituted your twin sister for the dead child. At least Mary Mar-Vell would have a home, even if you had to go to an orphanage. No one would ever know."

Billy practically leapt at the woman, "Who raised my twin sister? Where is she now? How will I know her?"

The old woman raised her hand, "You'll know her by this broken locket. She wears the other half, She was raised by a couple named ... ahhhhhh ... " but death struck, sealing the lips of the only person on earth who knew the name of Billy's unknown sister.

"She's dead," Billy thought, horrified. "She's given me the greatest news of my life. I've got a twin sister! She wears the other half of this broken locket ... Holy Moly! Mary Grey was wearing a broken locket!" He shouted, "KREE!"

As the mightiest figure in the world soared into the air, he thought, "So Billy has a long-lost sister. So what does that make me? Well, that must make me her big brother! I'll catch up with Mary's car and see about that locket."

He caught up ... just in time to witness a surprising scene. The limousine was parked outside the Grey's house, but there was a squad of police cars pulling up. "Help! Kidnappers!" a man, presumably her adopted father, was shouting. "They've kidnapped Mary Grey," Captain Marvel realised.

Within the hideout, Mary Grey put on a brave front. "You ruffians! What do you want of me?"

A tall, dusky-skinned man wearing a dark blue suit, different from the desperadoes who grabbed her, gave her a small, tight smile. "Nothing from you, my dear girl. You are merely bait for a trap. I am after much bigger game. I have been embroiled in an competition, you might say, for quite some time, and I have finally uncovered the key to victory."

The girl said, "The key? I don't understand."

The man replied, "I will indulge your curiosity." He instructed his men to open a large packing crate which lay in one corner of the room, revealing an advanced, alien-looking device. "The Psyche-Magnetron was hidden many years ago by an ancient civilisation, because they feared its power. With it, I will be able to master all they had to offer."

With a crash, the entrance to the room shattered open. "Locking the door on me, now that isn't nice," quipped Captain Marvel. He landed among them, angrily. "Put the girl down, now."

Mary Grey gasped, "Captain Marvel! Help!"

The dusky man cursed under his breath, "Hala, I wasn't ready yet." He addressed the desperadoes. "Monk, Yon, Rogg ... dispose of him."

"Scram, mister, or I'll slap ya silly!" rasped the first bruiser, built like a gorilla. Not quite realising just whom he was facing, he leaped forward and swung at the alabaster figure a haymaker that might have broken the neck of an ordinary man. The blow landed solidly on Captain Marvel's chin. Its only effect was to make the thug yell "Oww!" as his knucklebones were crushed.

"Tit for tat," murmured Captain Marvel and, smiling pleasantly, he shot his fist out at the thug's chin like a steam-driven piston. The thug sailed backwards through the air, landing among the others, and piled them all upon the pavement.

The leader finished making some adjustments to the ancient machine. "Hello again, Marvel."

Captain Marvel's face darkened. "Adam Rowan. You dare come here, and hurt this girl? You of all people?"

Adam smiled grimly. "I gathered she was important to young Billy, and planned to use her as bait. I didn't realise my kidnapping ploy would summon you here quite so effectively, however." He indicated the device. "With this I can conjure up anything ever devised by the super-science which granted us both our powers." He activated it, and a giant yellow robot appeared out of nowhere. "This is I.B.A.C. ... the Intelligent Biomechanical Assassination Construct ... the deadliest creation of even our star-spawned race!"

I.B.A.C. attacked, pummelling Captain Marvel with both fists and energy-beams from its eyes. Cap fought with the courage of Achilles but he found himself clearly outmatched. Finally, out of desperation as he found his strength ebbing under the deadly force of the robot, figured out a plan. He flew in front of the Psyche-Magnetron, drawing the I.B.A.C.'s fire... then ducked at the last instant, so the robot blasted the very machine that spawned it. I.B.A.C. faded into nothingness.

Adam opened his mouth to speak, but Captain Marvel rushed forward with the speed of Mercury, clamping his hand over the man's throat and silencing him. Frantically, he pulled a gun out of his jacket and fired it point-blank at the Judgement Leaguer. As the gun went off, a stray ricochet struck Mary Grey. Enraged, Marvel punched Adam repeatedly, while the snivelling criminal begged for mercy. "I'll give you aid ... riches ... anything you desire...!"

"Can you give me my parents' lives, Adam? Answer me... can you give life again to those you did slay?" Finally, after he pounded the villain into unconsciousness, Marvel regained his composure and stopped short of outright murder. He won the fight, but felt no satisfaction from it. As he pondered the futility of vengeance, Marvel saw that the damaged Psyche-Magnetron was running out of control and ready to explode. After his hard-fought battles, he only had enough strength left to carry one person to safety; he picked up Mary and raced to the exit, just ahead of the mighty explosion!

As Marvel set the girl down, she returned to consciousness. "Ow, my head. What happened? I thought I was shot."

Captain Marvel knelt down and carefully examined her. "It appears the bullet only creased your scalp, knocking you out. But you're fine."

Mary Grey noticed him again. "Captain Marvel! You saved me. You were wonderful."

Captain Marvel nodded, and smiled at her softly. "Forget it. But Mary ... I have a very important question to ask you. Do you have the other half of this broken locket?"

Mary took it from his hand, and removed the chain from her neck. "Why, yes," she said, comparing the two, "They fit. What does it mean?"

Captain Marvel audibly gulped. "It means you are Mary Mar-Vell ... the twin sister of Billy Mar-Vell!"

Mary's eyes widened. "It must be the truth. Nurse Sarah Primm once told me the broken locket would change my whole life. Billy Mar-Vell ... my brother. How wonderful! But where is Billy? Why didn't he come?"

Captain Marvel grinned, "He did come. KREE!" In a blinding flash of lightning, Captain Mar-Vell returned to his younger self.

Mary stepped back in shock. "Billy! I saw Captain Marvel change right into you!"

Billy nodded, "Sure, Mary. Being in the family, why shouldn't you know my secret?"

She stepped forward and gave him a hug. "Billy! My brother!" She kissed him on the cheek. "This is the happiest moment of my life!"

"Mine too," he said.

In the happiness of the family reunion, the two did not notice that behind them, the rubble of the damaged building stirred. Where once was the greedy and envious explorer Adam Rowan, now stood Black Ronan the Pharaoh Inquisitor! With a blast from his Cosmi-Rod, Billy Mar-Vell was rendered unconscious.

"Billy!" she screamed, "speak your magic word! Oh, you can't ... you're unconscious ... you can't say KREE!"

Mary Mar-Vell said the word for the first time, and instantly there was an answering roll of thunder ... a blinding flash of lightning ... and after some instants she was transformed into a woman who looked a lot like Mary, except with a black costume and a domino mask with points coming from the top.

"It happened! I changed! I feel strong ... powerful ... " she said, as she saw Black Ronan flying toward her. "Golly! It doesn't take the wisdom of Minerva to see that my telekinesis will sure come in handy here,"

She reached out with her mind, instinctively using her powers, and tore the Cosmi-Rod from Black Ronan's grasp as he landed before her. "Hala!" he swore in shock as he noticed her lightning bolt insignia. "So, you have the powers of that old fool Eon as well. It matters little. You can die just as easily as he can."

Her face darkened. "I don't know how, but when I changed, I seem to have absorbed some of Captain Marvel's memories as well. And I know you killed our parents!" She flew at him with the fleetness of the goddess Zephyrus, channelling through her attack all the skills of an experienced Kree warrior.

Black Ronan was taken aback, but soon entered into the fray with his physically smaller opponent. They each found that their blows had no effect on the other, though Mary's fury forced the other to step back. "You won't get any further with me than Captain Marvel ever did, my dear."

She said angrily, "The code of our race was a simple one: fight with honor, die with honor." She reached out with her telekinesis, moving his Cosmi-Rod behind him. "And this is just how Captain Marvel would finish off!" As he braced for her attack, the hammer-shaped weapon flew forward, smashing into the back of his helmet, knocking him unconscious.

Billy sat up and rubbed his head. "Captain Marvel couldn't have done it better himself. Boy, what a sister I have!"

She knelt down to him. "Thank you, Billy. I can't tell you how much it means to hear you say that."

Billy stood up, "I think we better transport Black Ronan to a holding facility, I know just the place. KREE!" Captain Marvel leaned down, flinging the unconscious form of their foe over their shoulder, and the two soared into the air. "You're my sister as well as Billy's," he said. "So your name in this form is ... Mary Marvel Girl!"

She beamed, "Mary Marvel Girl. Why, I love it! Where shall we go?"

He said, "Come with me for awhile." The pair flew towards New York City, landing in the mansion of the Judgement League Avengers. They were greeted at the facility by Marko Xavier, the group's financier and administrator.

He smiled, "Hello Captain. Who is your friend?"

Captain Marvel said, "We need our strongest restraints to hold our captive," he indicated the unconscious villain. "And then, we need to ask your advice."

After Black Ronan had been secured, the pair relayed their story to Xavier. 'Fascinating," he said. "Mary, do you mind if I do a scan of you in our lab? It won't hurt ... not that anything much could hurt you now anyway."

She looked at her brother unsurely, but he nodded his encouragement. "Okay, I guess. It would sure be good to know how I got these powers?"

Later, in the lab, Xavier examined the results. "The energy bombardment somehow caused Mary's genetic structure to be melded with Captain Marvel's. While Marvel was apparently unaltered by the event, Mary is now a perfect hybrid of Kree and human genes. In addition, she possesses all of Marvel's Kree knowledge and training. The energy also seems to have activated Mary's latent metamutant talents, hence the telekinesis, which Captain Marvel doesn't have."

Mary blinked, "I'm a metamutant?"

Xavier nodded, "Many people have abilities which never manifest until some extreme circumstance brings them on, and in your case, the explosion of the Psyche-Magnetron was sufficient. And since you are a metamutant, Mary, I think there's something else we can discuss: a project which I and some of the others have been working on, that we call … the JLX."

References:

Since Marvel Girl never had much of an origin in X-Men #1, and since the amalgamated Carol Danvers is relegated to being the Huntress, I used some elements from the origin of Ms. Marvel as well. Some of the prose in the story is lifted from Otto Binder, Captain Marvel Adventures #18 and The Return of the Scorpion. I have also lifted liberally from Roy Thomas's "Vengeance Is Mine!" in Captain Marvel #18 (thanks to J. Kevin Carrier) and from Electric Avatar's story "The Power of Eon."